Optical: systems and elements – Single channel simultaneously to or from plural channels – By partial reflection at beam splitting or combining surface
Reexamination Certificate
2001-03-30
2002-12-24
Epps, Georgia (Department: 2873)
Optical: systems and elements
Single channel simultaneously to or from plural channels
By partial reflection at beam splitting or combining surface
C359S639000
Reexamination Certificate
active
06498686
ABSTRACT:
BACKGROUND
The present invention relates to the art of optical display systems. More particularly, the present invention relates to optical display systems having light valves and color displays.
In order to reduce the cost of light valve projection systems, it is common practice to employ an optical system with a single fast-responding light valve together with some sort of color selecting means (for example, a color wheel) operating in a sequential color mode. In such systems, the light valve rapidly displays monochrome frames of primary color information (generally three times faster than the normal refresh rate used for non-sequential systems.
For instance, to display a frame of a color image, the frame is displayed by projecting three rapid sub-frames, each sub-frame being of a single primary color. That is, to project one frame of a color image, a completely red image sub-frame, a completely green image sub-frame, and a completely blue image sub-frame are projected one after the other, very rapidly.
The rapid display of the monochrome sub-frame information on the light valve is synchronized with the colors passing through the color selecting means. This rapid succession of primary color images creates the impression of a single full color image in the mind of an observer due to the phenomenon of color persistence—the well-known fact that the human eye averages together information received over periods of a fifteenth of a second or so.
However, if the observer's eye is not stationary relative to the image during the display on such a device (due to natural rapid saccadic motion of the eye, for example), the relative motion will cause the successive primary color images to fail to overlap perfectly on the viewer's retina. The viewer will perceive incorrectly colored edges to bright objects under such circumstances, which will disappear when the relative motion ceases. This creates the annoying impression of a brief flash of color in situations where none was expected —a situation frequently referred to as “sequential color visual artifacts. ” The phenomenon is worst for two or more small white objects spaced apart horizontally and displayed against a black background. The natural saccades of a viewer's eyes (which are most rapid in the horizontal direction) are frequently sufficient to cause strong and nearly continuous artifacts under such circumstances.
There is a need for a technique and an apparatus to alleviate sequential color artifacts.
SUMMARY
The need is met by the present invention. According to one aspect of the present invention, an optical display system includes a lenticular array for focusing color light beams onto a plane forming a spatial mix of the colors of the beams and an optical translator for shifting the spatial mix of the colors of the plane.
According to another aspect of the invention, a method of displaying a frame of a color image is disclosed. A first sub-frame is projected, the first sub-frame having a spatial mix of primary colors and a second sub-frame is projected, the second sub-frame having a permutated the spatial mix of the primary colors.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in combination with the accompanying drawings, illustrating by way of example the principles of the invention.
REFERENCES:
patent: 4615595 (1986-10-01), Hornbeck
patent: 5061049 (1991-10-01), Hornbeck
patent: 5353133 (1994-10-01), Bernkopf
patent: 5715029 (1998-02-01), Fergason
patent: 5751383 (1998-05-01), Yamanaka
patent: 5835256 (1998-11-01), Huibers
patent: 5864374 (1999-01-01), Ito et al.
patent: 5959704 (1999-09-01), Suzuki et al.
patent: 5971546 (1999-10-01), Park
patent: 6005722 (1999-12-01), Butterworth et al.
patent: 6020940 (2000-02-01), Ishikawa et al.
patent: 6243055 (2001-06-01), Fergason
patent: 6262786 (2001-07-01), Perlo et al.
patent: 6327093 (2001-12-01), Nakanishi et al.
patent: 6332684 (2001-12-01), Shibatani et al.
Sony, LCD System Semiconductor Selection Guide, found at http://www.sony.co.jp/en/Products/SC-HP/GUIDE/PDF/LCDE.pdf.
Epps Georgia
Hewlett--Packard Company
Seyrafi Saeed
LandOfFree
Single light valve projector with reduced sequential color... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Single light valve projector with reduced sequential color..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Single light valve projector with reduced sequential color... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2935895